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E36 (1991 - 1999) The E36 chassis 3-Series BMW was a huge hit among driving enthusiasts from the first moment the car hit the pavement. The E36 won numerous awards over the years it was produced and is still a favorite of many BMW enthusiasts to this day! -- View the E36 Wiki

At night i can imagine that the headliner having like a moonlight glow. so i want to achive that.

Im looking to buy 5 blacklight LED's single bulbs.

I have no clue what im looking for here.. and the cheapest i found was 1.99 on amazon each... i though LED's were cheap? f***

Then im looking for a small dimmer switch that i want to install down near the steering wheel.... like below the column but on that lower dash area. so a small black dimmer so i can control the blacklight that is emitting from these.

How do i wire these to make them all the same brightness and run off the dimmer? i cant imagine it... I know it would be a pain... but can you draw a picture? im going to try to draw one too... to see if my idea is right. but would i be wiring up in parellel or in series? series will cause them all to spilt power and parrellel wouldnt right?

would i need any resistors or anything of the sort?

what power line should i be thinking of taping into?

and then the ground.... just anywhere on the chassis?

does either of these look right? sorry if they are terrible or wrong... im just guessing

have ordered leds fromthese guys, and iirc they had decent prices. (yet *another* project that is on the backburner....)

I want to change my angel eyes on my X5. I want to change them to the new angel eyes. The bright super white. Any idea on what I should be looking for in this site? I don't want to order the wrong one.

have ordered leds fromthese guys, and iirc they had decent prices. (yet *another* project that is on the backburner....)

I want to change my angel eyes on my X5. I want to change them to the new angel eyes. The bright super white. Any idea on what I should be looking for in this site? I don't want to order the wrong one.

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Ashlins x5 has white angel eyes in them, I bought them off eBay. There not as bright as the new cars but wayyyyyy better than the yellow. I would figure the new ones are xenon powered or something more than just the bulbs.
Franklyn sounds like a fun project...you need the sunroof motor cover? I may have one.

Surprised no one brought this up, but a dimmer switch does not work the way you would think on LEDs.

LEDs are like switches, either ON or OFF. To properly dim LEDs you need to modulate the voltage very quickly (called Pulse Width Modulation). Rather than try to give you an LED 101 course, just look up some pre-built LED driver that has what you want on it. It won't be as cheap as your LEDs (yes, $2 for Blacklight LEDs are cheap).

What you write may apply to the Z3 and Compact. A E36/2/4 dimmer unit, however, does use Pulse Width Modulation, but with a linear, ca. 20-100% dimming curve meant for incandescent lamps. To provide uniform and sufficient dimming, a PWM dimmer for LEDs needs a non-linear (exponential or square-law) dimming curve that ranges from nearly 0 to 100%. I couldn't find a suitable automotive LED dimmer when I looked a few years ago, and ended up designing one to dim a pair of 10 mA LEDs in series.

You face the same issue when you change the interior lights to LED. I square the linear, PWM, ramped lighting signal from the ZKE (and change, say, 10% on to 1% on) which seems to do the trick.

What you write may apply to the Z3 and Compact. A E36/2/4 dimmer unit, however, does use Pulse Width Modulation, but with a linear, ca. 20-100% dimming curve meant for incandescent lamps. To provide uniform and sufficient dimming, a PWM dimmer for LEDs needs a non-linear (exponential or square-law) dimming curve that ranges from nearly 0 to 100%. I couldn't find a suitable automotive LED dimmer when I looked a few years ago, and ended up designing one to dim a pair of 10 mA LEDs in series.

You face the same issue when you change the interior lights to LED. I square the linear, PWM, ramped lighting signal from the ZKE (and change, say, 10% on to 1% on) which seems to do the trick.

I have no clue what im looking for here.. and the cheapest i found was 1.99 on amazon each... i though LED's were cheap? f***

Then im looking for a small dimmer switch that i want to install down near the steering wheel.... like below the column but on that lower dash area. so a small black dimmer so i can control the blacklight that is emitting from these.

How do i wire these to make them all the same brightness and run off the dimmer? i cant imagine it... I know it would be a pain... but can you draw a picture? im going to try to draw one too... to see if my idea is right. but would i be wiring up in parellel or in series? series will cause them all to spilt power and parrellel wouldnt right?

would i need any resistors or anything of the sort?

what power line should i be thinking of taping into?

and then the ground.... just anywhere on the chassis?

does either of these look right? sorry if they are terrible or wrong... im just guessing

Have you got those led lights. Even I am thinking of purchasing some led lights

Surprised no one brought this up, but a dimmer switch does not work the way you would think on LEDs.

LEDs are like switches, either ON or OFF. To properly dim LEDs you need to modulate the voltage very quickly (called Pulse Width Modulation). .

Cool idea, though.

Sorry but incorrect! The light output from an LED is directly proportional the current through it. You can control the brightness of the LED using PWM also but it's done to reduce the power dissipation of the dimming controller not because of the LED.
If you use a linear control the power NOT delivered to the LED has to be dissipated by the control device. When the LED is fully dimmed the controller dissipates all the power. When you use PWM the only dissipation in the controller is due to the losses in the internal switching circuits. You are actually turning on the LED at full brightness but for a short time and off for a time at a rate fast enough that your eye can't discern the flicker. As you increase the ratio of on to off the LED appears to be brighter and when you decrease the ratio of on to off it appears to be dimmer.

Quote:

Originally Posted by johnf

What you write may apply to the Z3 and Compact. A E36/2/4 dimmer unit, however, does use Pulse Width Modulation, but with a linear, ca. 20-100% dimming curve meant for incandescent lamps. To provide uniform and sufficient dimming, a PWM dimmer for LEDs needs a non-linear (exponential or square-law) dimming curve that ranges from nearly 0 to 100%. I couldn't find a suitable automotive LED dimmer when I looked a few years ago, and ended up designing one to dim a pair of 10 mA LEDs in series.

You face the same issue when you change the interior lights to LED. I square the linear, PWM, ramped lighting signal from the ZKE (and change, say, 10% on to 1% on) which seems to do the trick.

John, you can do the same with an audio taper potentiometer for LED control. The issue when you replace an incandescent with an LED is the huge difference in currents required for illumination. If you put an LED in a circuit design for incandescents your control range for the LED is at the very end of the control so you essentially have none. You can put a resistor in series with the control to rescale the current and get good control range.

Sorry but incorrect! The light output from an LED is directly proportional the current through it. You can control the brightness of the LED using PWM also but it's done to reduce the power dissipation of the dimming controller not because of the LED.

In practice, you can treat LEDs that way from, say, 25% to 400% (pulsed) of their static, maximum current. The further you stray from that range, however, the more an LED diverges from a linear ideal, because of its semiconductor non-linearity and its inexact manufacture. This is especially true of white LEDs. They must be matched or "binned" during manufacture (into perhaps 4 x 3 = 12 different bins) to have any hope of producing a group of them with a consistent hue and intensity. Even then, the hues and intensities within a group will diverge if you decrease their drive current much below a minimum value, their so-called "grouping current". This might be 5 mA for a 20 mA white LED – which is not much dimming! Dimming an LED with PWM not only saves power, it also maintains its hue as you go lower, and dimming a string of LEDs with PWM keeps their intensities consistent.

As a practical example, I have a couple, series-wired, white LEDs in my dome light that illuminate the center console. I pulse width modulate them: with a 100% duty cycle, to light a map or a list of directions, and with a 1% duty cycle to provide ambient lighting. If I am unlucky, one of the LEDs might not even stay lit, if instead, I were to reduce their current from 10 mA to 100 uA – to say nothing of how their hues might change.

Quote:

John, you can do the same with an audio taper potentiometer for LED control. The issue when you replace an incandescent with an LED is the huge difference in currents required for illumination. If you put an LED in a circuit design for incandescents your control range for the LED is at the very end of the control so you essentially have none. You can put a resistor in series with the control to rescale the current and get good control range.

The issue I have had with LEDs vs. incandescent lamps is how much more linearly a LED's brightness changes with voltage and current compared to an incandescent filament, as in somewhat linearly vs. very non-linearly. (I think that is what you mean.) I like your idea of using an audio taper potentiometer in series with a resistor, which will also protect the pot from shorts. If we set aside everything I wrote earlier, I suspect, however, it might only be a simple solution for fairly low LED currents. I get the impression that rather few use audio taper potentiometers as power rheostats. I can't find any over 2W (and those are pricey), and the pot datasheets I have browsed give no guidance for the maximum current the pot can carry approaching zero ohms.